(function(){
	let Land = window.Land = function(){
		this.w = 336;
		this.h = 112;
		this.x = 0;
		this.speed = 2;
	}
	
	Land.prototype.init = function(){
		game.ctx.drawImage(game.R.land,this.x,game.canvas.height * 0.75);
		game.ctx.drawImage(game.R.land,this.x + this.w,game.canvas.height * 0.75);
		game.ctx.drawImage(game.R.land,this.x + this.w * 2,game.canvas.height * 0.75);
		
		//填充大地底色
		game.ctx.fillStyle = 'rgb(222,216,149)';
		game.ctx.fillRect(0,this.h + game.canvas.height * 0.75,game.canvas.width,game.canvas.height * 0.25 - this.h)
		
	}
	
	Land.prototype.move = function(){
		this.x -= this.speed;
		if(this.x < -this.w) this.x = 0;
	}
})();